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Nov. 28, 1939. M- w, MCCQNKEY BRAKE Original Filed Dec. 3, 1923 gn/uente@ @27m/gy NZZ/2@ bho/numana @Wg Reiued Nov. 28, 1939 UNITED STATES PATENT oFFIcs BRAKE Montgomery w. monkey chicago, nl.. ae-

signor to General Motors orporation, Detroit, Mich., a corporation of Delaware riglnal No. 1,837,465, dated December 22. 1931,

Serial No. 678,236, December 3, 1923. Application' for reissue April 9, 1938, Serial No.

s claim. (ci. 121-38) This invention relates to booster brakes. that is. brakes which are applied by power or partly by power under-the control of an operator, and is illustrated as embodied in a motor vehicle having such brakes applied under the control of the driver by power derived from the intake manifold of the engine.

Brakes of this character as heretofore designed have been open to one or both of two objections in. that either the control was not sufllciently sensitive to permit the driver to apply the brakes accurately, or if such sensitive control was provided, it was by some kind of throttle actionin which it was extremely diiiic'lt for the driver to gage the eiiect on the brakes.

An object of the present invention is to provide a very sensitive control for such power brakes in such a manner that the operator can readily determine the effect on the brakes. In one desirable arrangement, a driver-operated controlling member, such as a brake pedal, operates connections constructed to apply power to the brakes to an extent which is a predetermined multiple 0f the power applied to the pedal or its equivalent,

the parts preferably being so arranged that when the engine is not running, or when for any other reason power is not available, the vsame pedal or other member can apply the brakes manually. In the embodiment shown in thev drawings, movement of the brake pedal controls a valve which admits suction from the intake manifold or other source to a cylinder and piston connected to the brakes, the valve being of such a type that it automatically cuts olf the suction when the desired effect on the brakes is reached.

Another feature of the invention relates to the provision of an indicator, shown as a visible indicator or gage which canl be mounted on the instrument board, operated by the same power which is applied to the brakes so that it shows to the driver how much pressure isbeing exerted on the brakes. In the illustrated embodiment, a gage is connected to the vabove described cylinder in such a. manner as to be operated by the suction acting on the brakes.

Other objects and features of the invention, including a novel valve operating automatically as explained above, and other novel combinations of parts and desirable particular constructions, will be apparent from the following description of one illustrative embodiment shown in the accompanying drawing, in which:

Figure 1 i's a diagrammatic longitudinal vertical section through the chassis of an automobile having brakes of the type described;

Figure 2 is a vertical section through the operating parts shown in side elevation in Figure l; and

Figure 3 is a front elevation ofthe gage.

In the arrangement selected forillustratiomthe 5 invention is embodied in an automobile having a chassis frame I0 supported by front and rear wheels having front brakes l2 and rear brakes Il. 'Ihe front brakes are shown as being operated by links I6 and I8 connected to arms 20 on a rock shaft 22, and the rear brakes are shown as being operated by links 24 and 26 connected to arms 28, also secured to the rock shaft 22. As the brakesV themselves form no part of the present invention, further description is not considered necessary, as any desired particular construction may be adopted. The shaft 22 is \^rocked to apply the brakes by a link 30.

lAccording to the present invention, the link 30 is connected to a bell crank lever 32 freely pivoted at 3l on a brake pedal or equivalent controlling member lili.L The pedal 36 is shown as being iulcrumed at 3B and as being urged toward its idle position by a\ return spring 40 in the usual manner.. The brake pedal 36 is formed with an abutment I2 arranged to engage, after aslight lost motion, an abutment M on the bell crank lever 32 to apply the brakes manually if the engine is not running, or if forany reason power is not available. This particular auxiliary connection for applying the brakes manually, including a device such as the bell crank ,lever 32 is claimed in Patent No. 1,580,221, granted to E. W. Seaholm upon April 13, 1926. It is not my intention tor claim any subject matter claimed in the said ,Sea-A holm patent in this present application.

While the brakes can be applied manually as described if the engine is not running, it is the intention that whenever the engine is running they will be applied by power shown in the present instance as derived from the intake manifold. As one desirable construction permitting such application of the brakes, a piston 46 is provided with a connecting rodV 48 connected to the bell crank lever 32 by a link 50, there being a slot 52 to allow lost motion when the brakes are applied manually. The piston 46 is arranged ina cylin-y der 5l which may, .if desired, have a cover 56 to keep out dirt, and which is shown as being provided with ports 58 to allow the pressure of the atmosphere to act constantly on the upper surface of the piston.

Preferably formed as part of the same casting as the cylinder 5I is a smaller valve cylinder 60 shown as being constantly in communication `cating.'with the atmosphere through the open end of the valve cylinder 69.

Arranged in the valve cylinder is a valve piston 12, shown in its idle position in Figure 2,

that is, in the position which it occupies when the brake pedal is fully raised and the brakes are ot.' When the pedal is depressed to apply the brakes, the valve piston 12 is depressed by ra spring 14 confined between the Vpiston and an abutment 16 on a connecting rod 1B, which is in turn pivotally connected to a link. Bil pivoted to the brake pedal. The rst depression of the pedal moves the valve pistonl! downwardly to a sumcient extent to close the exhaust port 1li, and immediately thereafter continued depression of the valve piston begins to open the intake port 64. The suction from the intake manifold, acting through the ports 64 and 62, immediately begins to draw downwardly the piston 46, thus applying the brakes, and also immediately begins to urge the valve piston 12 upwardly. It is to be noted that the abutment 16 is provided with small ports 82 so that the vacuum in the cylinders 60 and 54 is always the same. When the upward pressure on the valve piston 12 becomes sumcient, as the vacuum builds up inside of the two cylinders, to balance the pressure downwardly through the spring 14 from the pedal 36, the valve piston moves upwardly to cut off the port 64. At this time the parts are balanced with the valve piston 12 closing both of the ports 64 and 19, and with the pressure on the brakes from the piston 46 a predetermined multiple of the reaction against the pedal 36 through the compression of the spring 14; because of the fact that the piston 46 is of greater area than the piston 12, and both are subjected to the same suction. For this reason the feel of the pedal is the same as if thebrakes were being applied manually, '.except that it is always a predetermined fraction of the pressure which would be required ifv power were not being used.

Ii' the pedal 96 is further depressed, the spring 14 will again urge the piston 12 downwardly,

Iopening the port 64, until the vacuum in the two cylinders again builds up to such an extent that the valve piston 12 is again sucked up to cut oi! port 64, at which time the parts again balance with the pressure on the brakes the same multiple as before of the increased pressure on the brake pedal. In the particular arrangement shown in the drawings, the pressure applied to the brakes by the piston 46 is nine times the reaction against the brake pedal 36 through the spring 14. If the pressure on the pedal 36 is partly relieved, the

pressure on the spring 14 will be relieved in a corresponding degree, whereupon atmospheric pressure will push the valve piston 12 upward in the cylinder 6U to open the exhaustv port 19. As soon as the vacuum in the cylinders 54 and 60 is reduced to correspondto the new pedal pressure, the spring 14 will again push the valve piston 12 down to close the exhaust port 19, the various parts again balancing with the new pedal pressure and the new pressure onthe brakes.

When the pedal 36 is completely released and returns to its idle position under the influence of the spring 40, and in order to guard against any i possibility '0f the valve piston 'I2 sticking, the

piston is engaged by an abutment forma by s pair of lock nuts 64 on a rod 86 passing axially through the piston 12 and which is shown as being a continuation of the connecting rod 18. The

`rod 86 passes through a packing 88 held compressed by a bushing 90 to prevent loss of vacuum in the two cylinders. Preferably, the abutment 16 is adjustable to vary the compression of the spring 14 and thus change the limits of operation of the valve. by being held between nuts 92 and 94 threaded on the connecting rod 19.

' In order to indicate to the driver the pressure on the brakes, I consider it desirable to provide an indicator such a`s a gage 96 (Figure 3) connected by a exible tube 98 to a port |90 formed in the cylinder 54. The particular gage shown in the drawings is of the well known type in which a Bourdon tube is arranged to expand and contract, and in so expanding and contracting operates a pointer |02 moving over a scale H14.v A gage of this character is well adapted for mounting on the instrument board of a motor vehicle. It will be noted that the gage does not show the available power, but shows the power which lis actually applied to the brakes.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that particular embodiment or otherwise than by the terms of the appended claims. 'Ihe invention is shown embodied in brake-operating connections, and is well adapted for such use, butobviously at least some of the features are capable of useful embodiment in other connections than those shown, and for operating other mechanism than brakes.

I claim:

1. A valve for operating a uid power motor comprising, in combination with said fluid power motor, a source of substantially uniform pressure, a source of different fluid pressure, a valve casing having an exhaust port connected to said firstnamed source of iluid pressure and having an intake port connected to said second-named source of fluid pressure and having port means connected to said uid power motor, a valve member in the cylinder movable to different positions to connect said second source to said power cylinder or to connect the exhaust port to relieve the pressure in said uid power motor or to disconnect both of the ports from said uid power motor to isolate said iiuid power motor, said valve member dividing saidvalve cylinder into two chambers, one of which is permanently connected through said port means with the'power cylinder and the other of which is permanently connected with said tlrst-named source of fluid pressure whereby the valve member is acted on by a differential pressure with a force which bears a definite relation to the power exerted by said fluid power motor, a manually movable part, and a spring interposed between the valve member and said part in such a manner as to urge the valve member in a direction to disconnect the exhaust port from the port means and to connect the intake port to the port means when said part is moved in a direction to compress the spring, the spring being arranged to yield to` allow the valve member to move under the influence oi fluid pressure in the cylinder to cut ofl' the intake port.

2. Operating connections comprising, in combination, suction means for operating an operated means including a valve chamber having an intake port and an atmospheric portya connection for supplying suction to said intake port,

supplying suction therefrom to the suction op,

erated means and for connecting said atmospheric port to said su'ction operated means, a valv member having pressure faces positioned in the chamber and movable to connect the suction operated means with either oi said ports and arranged when in one position to disconnect the suction operated means from both ports,- and yielding means to move the valve member to disconnect the atmospheric port from the suction operated means and to connect the intake port in such a manner that the suction acting on lmember automatically move the valve member one face of the valve memberl and atmospheric pressure vacting on another face oi the valve combined operating cylinder and valve chamber formed together, said valve chamber forming part of a valve for controlling said operating cylinder and having an intake port and anex- 'haust port, a connection from said exhaust port t0 the atmosphere, a connection for supplying suction from said suction means to said intake polt, connecting means leading from the chamber i'or supplying suction therefrom to the operating cylinder which forms an operating device for the brake or .for connecting said exhaust port to said operating cylinder, a valve member in the chamber movableirom an idle pomtion successively to disconnect the exhaust port from the operating cylinder and then to connect the intake port to the operating cylinder and arranged when in an intermediate position to dis-l connect both ports, and a manually controlled device and a spring arranged to be compressed thereby to move' the valve member to `dkconnect the exhaust port and to `connect the intake port in such a manner that the suction building up in the chamber automatically moves the valvelmember against the resistance oi' the springV to disconnect both ports.

4. Operating connections for operating a brake` haust port,v a connection from said exhaust port to the atmosphere, a connection for supplying suction from said suction means to said intake port. connecting mean leading from the chamber for supplying suction therefrom to the operat g cylinderwhich forms an operating device for to said operating cylinder, a valve member in the chamber movable from an idle position successively to disconnect the exhaust port i'rom the operating cylinder and then to connect the intake port to the operating cylinder and arranged when in an intermediate position to disconnect both ports, said valve member dividing the valve chamber into two portions, one otvwhich is permanently connected with the operating e brake or for connecting said exhaustport f cylinder through said connection from the chamber to the loperating cylinder and the other of which is connected to the atmospheric connection, whereby the valve member is acted on by a diil'erential of prsure with a force which bears a deniterelation to` the force `exerted by the operating cylinder, and a manually controlled device and a spring larranged to be lcompressed thereby to move the valve member to disconnect.-

the exhaust port from the operating cylinder and to connect the intake port tothe operating cylinder in such a manner that the suction building up in the chamber automatically moves the valve member against the resistance of the spring to disconnect both ports, the structure being so arranged that relieving the physical pressure on the manually controlled device permits the suction in the chamber to move the valve member to connect the exhaust' port to the operating cylinder to reduce the suction in the valve chamber to a corresponding degree, whereupon the spring is operative to move the valve member back again todisconnect the exhaust port.

s 5. Operating connections for operating a brake comprising, in combination, suction means, a combined operating cylinder and valve chamber i'ormed together, said valve chamber forming a part of a valve for controlling said operating cyl- 'inder and having an intake port and an exhaust port, a connection from said exhaustport to the atmomhere, a connection for supplying suction from said suction means to said' intake port, connecting means leading fr'om the chamberfor supplying suction therefrom to the operating cylinder which forms an operating device for the brake or for connecting said exhaust port to said operating cylinder, a valve member in the chamber movabl from an idle position successively to disconnect the exhaust port 1 from the operating cylinder and then to connect the intake port to the operating cylinder and arranged when in an intermediate position to disconnect both ports,

and a manually controlled device and a spring arranged to be compressed thereby to move the valve member to disconnect the exhaust port and to connect the intakel port in such a manner that the suction building up in theA chamber automatically moves the valve'member against the resistance of the spring to disconnect'both ports,

in combination with a lost-motion device for positively returning the valve member to a predetermined initial position when the manually controlled device is returned to its idle position.

6. A. device o! the class described ior operating an operated member comprising, in combination', a connection to the external atmosphere, a source oi suction, a power cylinderand valve chamber formed integral with and arranged adjacent to each other and constantly in communicationwith each other. port means by which said power cylinder communicates with said valve chamber, a piston in the cylinder so arrangedthat relative movement of the cylinder and piston applies force as described, a conduit leading i'rom the valve chamber to said source oi' suction, valve mechanism controlling the conduit leading from said valve chamber to said Vsource oi suction, 'a passage leading from said cylinder and valve chamber to'said connection to the external atmosphere, yielding means arrangedto move the valve mechanism dividing the valve chamber into two portions, one of which is permanently connected through said port means with said power cylinder and the4 other of which is permanently connected through said passage with the atmosphere, whereby the valve mechanism is acted on by a diilerential pressure with a force which bears a denite relation to the force exerted by the power cylinder, and means for applying pressure to said 'yielding means and also for applying manual pressure to the operated member in case the suction means fails or is insufficient.

7. A device of the class described for operating an operated member comprising, in combination, a source of suction, a power cylinder and valve chamber arranged adjacent to each other and constantly in communication with each other, a conduit leading from said valve chamber to said source of suction, a piston in the cylinder so arranged that relative movement o1' the cylinder and piston applies power as described, a valve device controlling said conduit leading from said valve chamber to said source of suction, a

passage leading from said cylinder and valve l. chamber to the external atmosphere, a port providing said communication between said chamber and said power cylinder, an operator-controlled member, said valve device dividing the valve chamber into two portions, one or which is permanently connected through said port with the power cylinder and the other of which is permanently connected with the external atmosphere, whereby the valve device is acted on by a diierential of pressure with a force which bears a definite relation to the force exerted by the power cylinder, and a spring compressed by said operator-controlled member to move the valve device in a direction to admit suction to said valve chamber and cylinder and arranged to yield to permit the valve device to move to cut ot! the suction under the influence of an increase thereof building up in the valve chamber, and means for applying pressure to said operator-controlled member and also for applying manual pressure to the operated member in case the suction means fails or is insuicient.

8. A device oi the class described for operating a brake comprising, incombination, a source of suction, adjacent power and valve cylinders hav-` ing a connecting port. apower piston in the power cylinder, the valve cylinder having an intake port connected to said source oi' suction and an exhaust port connected to Vthe atmosphere, each of said ports being at times connected to the power cylinder, a valve device in the valve cylinder arranged for movement rst to disconnect the exhaust port to cut oi! the power cylinder from the atmosphere andthen to connect the intake port to connect the power cylinder with the source oi' suction, .and at an intermediate point to disconnect both ports to isolate the power cylinder. said valve device dividing the valve chamber into two portions, one of which is permanently connected through said connecting port with the power cylinder and the other of which is permanently connected with the external atmosphere whereby the valve device is acted on by a differential of pressure with a force which bears a deiinite relation to the force exerted by the power cylinder, a controlling member,v

brake in case the suction means fails or is insufficient.

9. A device of the class described Ior operating a brake comprising, in combination, a power cylinder and piston, a valve chamber, communicating passages connecting said power cylinder and said valve chamber, the chamber having intake and exhaust ports and arranged 'for communication with the cylinder through said com,- municating passages, a yieldingly operated oating valve member in the valve chamber controlling uid pressure for the power cylinder und arranged to be i, balanced automatically by a uniform i'iuid pressure on one side and by operating pressure and a different iiuid pressure on the other side, one of said uuid pressures being the pressure of the atmosphere, said valve member dividing the valve chamber into two portions, one oi which is permanently connected with the power cylinder through one of said communicating passages and the other of which is connected to the uniform iiuid pressure, whereby the valve member is acted on by the diil'erential erpressure with a force which bears a deilnite relation to the force exerted by the power cylinder and whereby when the operating pressure is balanced by the diierentlal of pressure the valve member moves to disconnect both ports to isolate said power cylinder from the intake port and the exhaust port oi' the valve chamber to form a lapped position in such a manner as to hold the power piston stationarily supported with powerapplied,

and means lor applying operating pressure' to said` 

